Manufacture of stencils for duplicating apparatus



' duplicating ink to Patented July 13, l926.

UNITED STATES PATENT OFFICE.

PAUL GAMIION, OI FOREST-NEAR-BRUSSELS, BELGIUM, ASSIGNOR TO A. B. DICKCOM- PANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

MANUFACTURE OF STENCILS FOR DUPLIGATING APPARATUS.

No Drawing. Application filed December 12, 1921, Seriatfio. 521,866; andin Belgium December 22, 1920.

This invention relates to the manufacture of stencils for duplicatingapparatus, and it has more particularly for its object to provide animproved process for the manufacture of such stencils which will afiordconsiderable advantages compared with the processes employed hitherto,as will be perceived from the following description.

Stencils as employed hitherto have, as a matter of fact, the followingdrawbacks 1. A paraflin-coated stencil allows the pass through thecracks that are caused accldentally either through the usual handling,or by the stencil being carried along bythe type-writing machine inwhich it is being used, at the instant when it is being impressed by thematter that is to be duplicated, Such cracks give rise to ink spots onthe copies. v

2. Other kinds of stencils are not subject to the occurrence of thecracks referred to under 1, but they haveto be moistened before beingused in the typewriter. This moistening operation hasas its chiefdrawback, that of causing the parts of the typewriter to becomemoistened as well, with consequent rusting and deterioration of thoseparts. A stencil of that kind is not sufficiently thick (that is, hasnot sufficient body) and is diflicult to keep in correct position on theinking cylinders of rotary and other duplicating machines so that thematter on the stencil is not adapted to produce uniform copies.

The above-mentioned drawbacks are obviated by the present inventionwhich consists broadly in usingas the stencil a sheet of Japanese paper(such as is already in general use in this class of manufacture andcommonly known as Yoshino) impregnated uniformly with pharmaceutical orindustrial collodion, or a solution of celluloid with an addition ofcastor oil, and coated on one' side with a coat of paraifin, ceresinewax, or generally with a coat of a solidifiable fatty niineral,vegetable or animal substance.

This last coat is intended to maintain in a supple condition thecollodion or solution of celluloid with which the sheet is impregnat'ed;it also serves as a cushion or resilient underlay for facilitating thestencilizing of the coat of collodion or solution of celluloid by thetype characters of the typewriter.

It is to be noted that with this object in view the typing should bedone on that side of the sheet that is not coated with parafiin.

As a bath having a celluloid basis there may be used a suitable solutionof thislatter substance in one of its solvents, or in several 0 of thesetogether, such as ether, acetone, acetic ether, etc., to which solutionthere is added a certain amount of castor oil or other suitable similar.oil, such that the impregnated sheet shall have the requisite supplenessand thickness. Good results can be obtained by adding approximately 40%of castor oil to a 2 7?) solution of either collodion or celluloid.

A stencil sheet produced according to this invention possesses .body andneed not be moistened before being typed upon, and it can crack, andeven be creased or rumpled without any ink spots getting upon the coies.

he same advantages can obviously be obtained, although in a lesserdegree by using two sheets one placed upon the other, the first sheetbeing simply impregnated with collodion or a solution of celluloid,whereas the other sheet is simply coated with para'flin.

Or a single sheet may be used simply 1mpregnated with collodion or asolution of celluloid, and the supporting foundation or underlay beingcoated with a coat of parafa substance including collodion and castoroil, and, in addition, with a solidifiablematerial.

4-. A type-im ressible stencil-sheet having a base such as JapaneseYoshino coated with a substance including a cellulose compound v1,cca,aes

and castor oil, and, in addition,with a solidi- 6'. A type-impressiloiestencil-sheet having fiable material applied on oneside thereof. a basesuch as Japanese Yoshino coated with 5. A type-im ressible stencil-sheethaving a substance including a cellulose compound 10 a lease such asapanese Yoshino coated with and castor oil and, in addition, with a waxy5 a substance including a cellulose compound material applied on oneside of said sheet.

and Castor oil, and, in addition, with a waxy In witness whereof I afiixmy signature.

material. PAUL CAD ZPIONQ

